(1) Field of the Invention
This invention relates to an overhead conveying equipment.
(2) Description of the Prior Art
Various conveying equipment has hitherto been put into practice in which a vehicle is hung from an overhead rail and travels therethrough, the overhead rail often employing a monorail due to its simple construction. The monorail construction of the prior art, however, provided an auxiliary rail for preventing sideways swinging or derailment of a conveying vehicle, thereby being large-scaled. Therefore, in a case of using such construction in a shop, where the layout of equipment is often changed, the problem exists in that it takes much time to change the conveying route.
It is more difficult for a monorail provided with a feed line to change the conveying route. Battery operated equipment requires no feeder line, but has a problem in that exchange or charging of batteries is troublesome.
Remote control is desired to operate the vehicle to travel or stop, but in a case of using electric waves as the communication medium, various electric circuits in the shop are subjected to interference, whereas when light or infrared is to be used as the communication medium, signals cannot be transmitted when the light receiving unit that is usually provided on the vehicle enters into the dead angle, thereby being restricted in use within the shop if there are many obstacles to the light.
This kind of equipment often allows the conveying vehicle to move or stop as predetermined, such as reciprocation between the predetermined points or a stop at the station, other than the above remote control. In this case, a switch dog complicated in construction and of high accuracy has conventionally been used for the assignment of position, which has the problem of taking too much time to adjust or change its mounting position.